$5$ men or $7$ women can earn $Rs. 5,250$ per day. How much would $7$ men and $13$ women earn per day? (in $Rs.$)

Two men undertake a piece of work for $Rs. 600$. Individually,they can complete the work in $6$ days and $8$ days,respectively. With the assistance of a boy,they completed the work in $3$ days. The boy's share should be (in $Rs.$)

$A$ can do a piece of work in $24$ days,$B$ in $32$ days,and $C$ in $64$ days. All begin to do it together,but $A$ leaves $6$ days before the completion of the work. How many days did the work last?

$A$ and $B$ together can complete a work in $10$ days. They started together,but $A$ left after $2$ days and the remaining work was completed by $B$ in $12$ days. In how many days can $A$ complete the entire work while working alone?

$7$ men can complete a piece of work in $12$ days. How many additional men will be required to complete double the work in $8$ days?

$A, B$ and $C$ completed a work costing $Rs. 1800$. $A$ worked for $6$ days,$B$ for $4$ days and $C$ for $9$ days. If their daily wages are in the ratio of $5: 6: 4$,how much amount will be received by $A$ (in $Rs.$)?